fully believe kathleen’s speech about sam was foreshadowing joel and ellie’s relationship. let me elaborate.
“i know why you did what you did. but did you ever stop to think that maybe he was supposed to die?”
joel pulled ellie out of the hospital because he couldn’t bear the idea of losing yet another daughter. knowing he could’ve prevented that this time. he put aside firefly’s mission and ellie’s wishes. it could also point out to ellie’s survivor guilt—she was convinced she was supposed to die in that hospital. that it was her purpose.
“you think the whole world revolves around him? that he’s worth everything?”
ellie is slowly becoming joel’s something to fight for. when he stands upon sam and henry’s graves, he’s starting to realise that after 20 years, there’s suddenly something he could lose. someone he has to protect. ellie quickly becomes joel’s whole world, his something to fight for. and he’s willing to go an insane lenghts to protect her. there’s nothing in the world carrying that much value as ellie does for joel.
“well, this is what happens when you fuck with fate.”
the consequences of joel’s actions will eventually catch up with him. the love you can have for someone is strong—but it can also be dangerous, as craig mazin pointed in one of the interviews. joel dies directly because of the consequences of his love for ellie. and because of how much he was willing to do to prevent losing her.